A generic simple tutorial brought out by Broadbandsearch - an ISP in the US. It covers some basics about various resources and instructions for google searches and more.
This guide describes the various types of writing that medical writers work at, the jobs that are available in this area, an overall guide to writing and importantly lists several more resources.
PRISMA-S: an extension to the PRISMA Statement for Reporting Literature Searches in Systematic Reviews This is a journal article that provides a checklist of 16 reporting items for inclusion in reporting literature search resources and strategies. Each checklist item is detailed and includes examples, explanations and references.